Cell phone coverage is not universal in that cell phone towers are concentrated in urban areas and also along major thoroughfares. Thus, a user is often without cell phone service when at home in certain suburban and rural areas. But virtually all homes are capable of broadband connections through DSL or cable modems. Unlicensed Mobile Access—Global System for Mobile Communication (UMA-GSM) dual mode phones take advantage of these broadband connections by allowing a user to access the GSM network through a wired broadband connection via a wireless access point (AP).
An exemplary UMA dual mode phone 100 is illustrated in FIG. 1. As would be the case for any conventional GSM-enabled handset, phone 100 can place calls through a cellular radio access network 110. In this regard, phone 100 would communicate with a base station 115 through a private network 120 to a base station controller 120. Base station controller 120 routes the call to a core mobile telephone network 130. In contrast, however, to a conventional GSM handset, phone 100 can also communicate through an unlicensed mobile access network 140 using a wireless access point (AP) 150. AP 150 may be configured as an IEEE 802.11 AP, a Bluetooth AP, or with any other suitable Internet Protocol (IP)-based wireless protocol. AP 150 connects through Internet 160 to a UMA network controller (UNC) 170 that in turn also couples to core mobile telephone network 130. Whether a call (carrying either voice or data or both) is placed on cellular radio access network 110 or unlicensed mobile access network 140 is entirely transparent to the user. Indeed, a caller may roam from cellular to IP coverage (or vice versa) without any discernible service interruption.
The UMA architecture is thus a well-developed VoIP technology. It has not been exploited, however, for integration into analog telephone adaptors (ATAs) because of its considerable license fees and complexity. Accordingly, there is a need in the art for low-cost and improved UMA ATA solutions.
Embodiments of the present invention and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures.